I am missing a transmission multiplex?
Brian Butterworth published on UK Free TV If you are missing a single multiplex on a single frequency, it may be that you have a local source of interference - such as a VCR, games console or Sky Digibox - causing the problem rather than a poor signal from the aerial.
Try eliminating any such devices, and if one does appear to cause the problem, change it's RF output channel to a new value.
All questions
In this section
Monday, 7 April 2025
D
Darren Brown8:10 PM
Hi Chris
I have tried a signal booster and although it has boosted the signal (both strength and quality are now hovering at between 75-80%), it is still going off at around 8pm with total loss of signal on the previously mentioned channels. Other than repoint aerial, I don't know what else to try.
Darren
| link to this comment |
C
Chris.SE10:31 PM
Darren Brown:
Have you got the filter plugged into the input of the booster?
Please post the current Signal Strength and Quality figures for each multiplex.
Then turn the gain down slightly, check and post the new Strength and Quality figures for each multiplex.
| link to this comment |
Tuesday, 8 April 2025
D
Darren Brown3:28 PM
Hi Chris
Yes I have got the filter attached.
UHF 29 - Signal Quality = 90%, Strength = 70%
UHF 31 - Signal Quality = 95%, Strength = 70%
UHF 37 - Signal Quality = 90%, Strength = 75%
UHF 41 - Signal Quality = 100%, Strength = 90%
UHF 44 - Signal Quality = 95%, Strength = 90%
UHF 47 - Signal Quality = 90%, Strength =80%
After I turned the booster down:
UHF 29 - Signal Quality = 90%, Strength = 85%
UHF 31 - Signal Quality = 95%, Strength = 75%
UHF 37 - Signal Quality = 95%, Strength = 80%
UHF 41 - Signal Quality = 100%, Strength = 95%
UHF 44 - Signal Quality = 100%, Strength = 95%
UHF 47 - Signal Quality = 90%, Strength =85%
Of course, the acid test will be tonight to see if 5USA etc goes off completely.
Thanks
Darren
| link to this comment |
Wednesday, 9 April 2025
C
Chris.SE12:10 AM
Darren Brown:
This is looking a bit like too much signal. In that situation, the front end of the receiver is overloaded and signal strength readings go down because of the way AGC circuits work and so does the signal quality.
Turn the gain down a bit more and post the new figures.
The primary reason the filter needs to be on the aerial side of the booster is so you don't amplify the interfering mobile signal which could also saturate the booster as well as the TV receiver because the filter on the "wrong" side may not reduce it enough either.
| link to this comment |
D
Darren Brown9:26 PM
Hi Chris
I have turned the booster down again and have the following figures:
UHF 29 - Signal Quality = 70%, Strength = 70%
UHF 31 - Signal Quality = 75%, Strength = 70%
UHF 37 - Signal Quality = 90%, Strength = 80%
UHF 41 - Signal Quality = 85%, Strength = 75%
UHF 44 - Signal Quality = 85%, Strength = 80%
UHF 47 - Signal Quality = 80%, Strength = 70%
However com4 went off again at around 20.15 tonight. Signal strength was still at 70% but signal quality went right down to between 0 and 10% resulting in pixilation and loss of signal. But just out of curiosity, I put a 5G filter at both ends of the booster and the signal quality on com4 seems to have settled at between 30 and 35% and it seems ok. Hopefully, thats the end of it. I have everything crossed.
| link to this comment |
C
Chris.SE11:37 PM
Darren Brown:
Hmm, those figures didn't quite behave as I was anticipating.
Interesting what you've said about having the two filters.
It's going to be a case of a bit of experimenting, Leave both filters in place.
Try first turning the gain down a bit at a time and watch the figures.
The try turning the gain up a bit at a time and watch the figures.
Make a note of the figures as you go, as well as the position of the gain control.
What you are looking for is 100% Quality with as high a signal strength as possible, but what you have to watch is if there's too much gain the strength "figures" start to creep down again and it can then have a detrimental effect on the Quality.
I can only guess we may have a combination of factors here, changes in propagation conditions as dusk approaches and some interference compounding matters.
If you can't find an optimum, then maybe a change to Pontop Pike maybe the next best thing to try. Can you safely access your aerial yourself?
| link to this comment |
Thursday, 10 April 2025
D
Darren Brown1:09 AM
Hi Chris
I will keep tweaking it and see what I come up with. As for getting up on the roof for the aerial, I wouldn't attempt it. As it happens, I'm off work with a torn cartilage in my knee but even if I was fully fit, I wouldn't try it. I would rather get someone out to look at it but like I say ill see what I can come up with.
Thanks
Darren
| link to this comment |
D
Darren Brown3:51 PM
Hi Chris
I have turned the booster gain up again slightly and come up with the following:
UHF 29 - Signal Quality = 85 - 90%, Strength = 78%
UHF 31 - Signal Quality = 92%, Strength = 82%
UHF 37 - Signal Quality = 95-100%, Strength = 86%
UHF 41 - Signal Quality = 100%, Strength = 94%
UHF 44 - Signal Quality = 100%, Strength = 82%
UHF 47 - Signal Quality = 100%, Strength = 91%
I have also left both 5G filters connected. I think this is probably the best im going to get and I will of course be keeping an eye on com4 tonight to see if it goes off.
Darren
| link to this comment |
C
Chris.SE11:31 PM
Darren Brown:
HI Darren, well that's certainly looking somewhat better.
Here's another experiment you can try -
Leave the gain where you have it and put both filters in series on the input to the booster and see how that affects the figures.
Post the results of that, it will be interesting whatever they do.
| link to this comment |
Friday, 11 April 2025
D
Darren Brown6:07 AM
Hi Chris, I did have issues again last night. COM4 went off again at around 9pm with no signal at all. U&Dave also went off and im pretty sure thats on COM5 (Could have been another factor affecting that one, such as weather or something). Came back on at around 10.15pm but signal on COM4 was around 85% strength and fluctuating between 35% and 55% quality. I fiddled with the filters and tried both the 5G filters in series on the booster input . By the time I had finished messing about with them at about 11.45pm, I had the following:
UHF 29 - Signal Quality = 100%, Strength = 90%
UHF 31 - Signal Quality = 100%, Strength = 92%
UHF 37 - Signal Quality = 100%, Strength = 92%
UHF 41 - Signal Quality = 100%, Strength = 96%
UHF 44 - Signal Quality = 100%, Strength = 96%
UHF 47 - Signal Quality = 100%, Strength = 95%
It was still showing these figures at 6AM this morning. I just wish I could get it to stay on in the evenings'.
Darren
| link to this comment |
Select more comments
Your comment please!